I remembered reading a story about the cell chip when it was first announced
that the chip would link up with other cell chips to give your games a graphics
upgrade (PS3 + Sony TV + Sony DVR). Is that still gonna happen or was that cut?

Brock Samson: You didn't tell me Sasquatch was a... a dude.Steve Summers: What, you couldn't tell?Brock Samson: Not until I had to...[shudders] shave him.Steve Summers: What are you, shy?...

Originally posted by melloI remembered reading a story about the cell chip when it was first announced
that the chip would link up with other cell chips to give your games a graphics
upgrade (PS3 + Sony TV + Sony DVR). Is that still gonna happen or was that cut?

Probably cut.

"There's no bigot like a religious bigot and there's no religion more fanatical than that espoused by Macintosh zealots." ~Martin Veitch, IT Week [31-01-2003]

Hopefully IBM learned a lot from this, and intends to get the PPC back up to speed.

Out of the major 3 Chip suppliers only Intel has higher clocking parts. The POWER5 is a monster. The PPC chips have never really been the speediest clockwise but the architecture. I have hopes for Cell Processors in devices like STB and game machines, I just hope it's inexpensive to fab.

He's a mod so he has a few extra vBulletin privileges. That doesn't mean he should stop posting or should start acting like Digital Jesus.- SolipsismX

Originally posted by salmonstkHow much help do you think it would be if they moved to an iPod hard drive in the Powerbooks.

Not much. Fans can only ever be part of the answer in a space as restricted as a notebook. A lot of the difficulty is in finding ways to wick heat away from hot parts in tight places over to some place which a fan (or ambient air) can cool, and spacing them on the board so that the hot spots aren't clustered together. A smaller hard drive might make this incrementally easier, at the expense of yet another small heat source (iPod drives run pretty hot) and a lethal performance hit every time you needed the hard drive. If you think a 4200 RPM laptop drive is slow... It might work for, say, the 12" iBook or PowerBook, where space is severely constrained and HD capacity is less of an issue.

I'd also expect iPod drives to be more expensive than laptop drives, just because miniaturization usually comes at a premium, but the sheer volume of iPod production might offset that.

The optical drive is a worse culprit, especially if it can burn CDs and DVDs (writing to optical media generates lots of heat). But there are limits to how much it can be miniaturized, because it has to be able to accept (relatively large) optical media.

To those who didn't get it, or read it. (not T'hain Esh Kelch) I never suggested IBM (Apple) use a Cell processor. What I was getting at is what was learned in creating the processor, and if it could help push the G5's evolution process foreword.

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I dont expect CELL to be the major speed-revolution some people touted it to be a few years back..

And anyway, IBM is also developing the tecnology, so if it has anything the PPC could need, it sure will get it!

Toshiba, and IBM are united on this processor for the PS3. The article is essentially about IBM. It just headlines toshiba for some reason.

Originally posted by T'hain Esh KelchI dont expect CELL to be the major speed-revolution some people touted it to be a few years back..

I think it will be revolutionary for games. If you think about a game, they're usually a number of complex things happening simultaneously and a parallel computer is probably the best way to tackle this. AI off to one core, GPU on another, logic on a third, etc. It's an interesting way to tackle game design and I think it will succeed.

"Hearing a corrupt CEO like Cheney denigrate Edwards for being a trial lawyer is like hearing a child molester complain how Larry Flint is a pervert." -johnq

Originally posted by bungeI think it will be revolutionary for games. If you think about a game, they're usually a number of complex things happening simultaneously and a parallel computer is probably the best way to tackle this. AI off to one core, GPU on another, logic on a third, etc. It's an interesting way to tackle game design and I think it will succeed.

It's going to be more interesting than that, because cores in Cell are not like traditional CPU cores. They're fractional cores. Remember that integer-only G3-derived core that IBM clocked all the way up to 1GHz during the Eternal Reign of 500MHz? That was, in hindsight, a technological exercise for Cell. The idea is radical customization. You pick a bunch of cores with limited, specific functions and assemble them all onto a single chip with a high-speed fabric connecting them all, and off you go. The simplicity of each core means they can clock very high. Theoretically, they could each run at independent clock speeds, but I don't know if IBM will pursue that initially (it simplifies the design significantly to have everything running on the same clock).

Basically, this is like Book E, only more so, and more scalable to boot.

But one of the upshots is that every Cell platform will be a new development target. Development will be made somewhat easier to the extent that Cell platforms will share building blocks (and to the extent that the developers are up to speed on the relevant object-oriented design principles), but vendors will have to go all the way through the optimization phase for every Cell platform they target.

As for performance, it's hard to say. IBM appears to have gone back to one of their monopoly-era bad habits: overpromising and underdelivering.

I have a slightly different take on IBM in that as a monopoly they have never learned to compete. That is they never learned the importantce of technology for this group of customers (us).

IBM's monopoly has never been technology or computers as such, it is rather a monopoly of sorts with respect to services and making the customer feel good. IBM's traditional cusotmers where not concerned about technology as much as they where about having the service available.

IBM is attempting to take their in house design and build apparatus and compete with the rest of the world selling technology. The problem is the expectations of the customers are different. IBM's internal customers think nothing of tacking on a water chiller if that is what is needed to service their income generating customers. Thus the a different emphasis is placed on semiconductor design as displayed in IBM's failure with low power devices.

Dave

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Originally posted by Amorph
As for performance, it's hard to say. IBM appears to have gone back to one of their monopoly-era bad habits: overpromising and underdelivering.

Originally posted by wizard69I have a slightly different take on IBM in that as a monopoly they have never learned to compete. That is they never learned the importantce of technology for this group of customers (us).

I understand what you're getting at, but I'd say that they learned to compete by other means. The assumption that "competition" implies "the best product winning in an open market" is na&iuml;ve at best, and IBM realized that early on.

In my opinion, their lack of success at low-power and high-yield devices simply comes down to a combination of arrogance and lack of experience. The POWER4 is a great design given its target market, but it teaches you nothing about how to make bushels of CPUs that perform well on a >10W budget.

However, the last year or so of bluster coming from IBM is troubling. In the wake of the 13-year-long antitrust suit, they'd learned to be (relatively) humble to avoid attracting further attention. I hope they haven't been emboldened to revert to their old tricks, although given the fact and nature of the MS antitrust trial, which truly snatched defeat from the jaws of victory, I wouldn't be at all surprised if they've been emboldened again.

anyone notice the massive role IBM has in the next generation of the next-gen consoles? its producing the cell technology in the PS3, and its providing the G5-esque PPC processor for xBox 2. they're gonna be rolling in cash in the next few years...

Originally posted by wizard69I have a slightly different take on IBM in that as a monopoly they have never learned to compete. That is they never learned the importantce of technology for this group of customers (us).

I would disgree with your statement greatly. Microsoft, as vendor of an operating system to 95% of the computer market is about as close to a monopoly as you are likely to see in the business world (for now). IBM on the other hand must indeed be very competitive in order to maintain their marketshare in the PC business, if they stop being competitive, their marketshare is likely to erode rather rapidly.

My point is that just because a corporation is large does not mean that you can automatically assume that they uncompetitive.

Originally posted by Amorph
However, the last year or so of bluster coming from IBM is troubling. In the wake of the 13-year-long antitrust suit, they'd learned to be (relatively) humble to avoid attracting further attention. I hope they haven't been emboldened to revert to their old tricks, although given the fact and nature of the MS antitrust trial, which truly snatched defeat from the jaws of victory, I wouldn't be at all surprised if they've been emboldened again.

At this time I think it is simply a matter of not having a clue when it comes to mass production. As public as the fiasco with the 970FX is I can't believe that there isn't a huge amount of embarassment at IBM right now. It is not like it is a secret that IBM couldn't meet the requirements of one of their customers.

Personally I hope that Apple has long term plans to keep Freescale on board. Either that or they corral somebody else into the PPC fold. If Freescale can't handle high performance electronics maybe TI or somebody else can take up the slack. Freescales offerings for the portable market are pretty good and have been for some time. The problem is that they are just that pretty good and are no longer examples of the best that can be had. If Freescale can retake that leadership position (high performance, low Power) agian I could see Apple staying with them a bit longer.

I've been reading a bit here and there about Cell, and I'm pleasantly surprised. The ultimate victory for cell, in my opinion, would be the death of embedded bloatware. That might not make any sense to you guys, but take a look at a PocketPC. It's the kind of travesty that occurs when businesses think it's too expensive to develop hardware solutions, and instead just get devices that can do everything, and write software for them. If getting cell chips is more or less like getting ASICs, which I think it will be, it will make embedded hardware NOT SUCK.

Plus, I fully expect that the Macs of the future will use cell or something like it. The current vein of processor design is ready to keel over and die.

Kickaha and Amorph couldn't moderate themselves out of a paper bag. Abdicate responsibility and succumb to idiocy. Two years of letting a member make personal attacks against others, then stepping aside when someone won't put up with it. Not only that but go ahead and shut down my posting priviledges but not the one making the attacks. Not even the common decency to abide by their warning (afer three days of absorbing personal attacks with no mods in sight), just shut my posting down and then say it might happen later if a certian line is crossed. Bullshit flag is flying, I won't abide by lying and coddling of liars who go off-site, create accounts differing in a single letter from my handle with the express purpose to decieve and then claim here that I did it. Everyone be warned, kim kap sol is a lying, deceitful poster.

Now I guess they should have banned me rather than just shut off posting priviledges, because kickaha and Amorph definitely aren't going to like being called to task when they thought they had it all ignored *cough* *cough* I mean under control. Just a couple o' tools.

Originally posted by AirSlufCell is going to be a bitch to write software for

I'd bet money that Cell is much easier to write software for, network structure and all, than x86. As far as I can tell, the min-cost network calculations are in hardware, and transparent to the user. Compilers will be made, and Cell has huge potential. The basic idea is clearly the direction of 21st century computing, regardless of the success of the early modules.

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It is a new paradigm and Sony has not yet put software dev kits in the mainstream.

Obviously. The chip doesn't exist yet. Furthermore, IBM would probably be sending the dev kits. What's exciting is the idea and the potential. Most people who know agree.

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It is a conscious tradeoff of more less individually capable units available to the programmers and independently pipelined

A 5 stage pipeline (or less) can be built without any real bloat. A 750 without any FPU and large L2 doesn't dissipate much power. If a Cell has 30 750 cores like this, that's less than 30W and a lot of computational grunt.

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It is a conscious tradeoff of more less individually capable units available to the programmers and independently pipelined. meaning each unit will be super-linearly slower than you might expect for the Hz too.

Sure, but you have way more of them, and generally speaking different parts of the same program require different functions of the CPU. So a conditional block, an integer block, and a memory access block working in parallel will be nice.

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It will shine for the specific multi-tasked, multi-simulation and entertainment arena it is targeted at--if you can get enough programmers to care to spend the time to learn how to best use it. That will be hard because there aren't ANY examples to use. That whole area will have to be bootstrapped, and that will take some time.

The basic PPC instruction set is really pleasant to program in. The mincost stuff is abstracted. Compilers will follow. Intel wrote great compilers for Itanium. Think of Cell as what Itanium should have been.

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Cell has potential, but that's all it is right now--potential. And that potential has been dumbed down an order of magnitude or more since the original hyperbolic announcements. I will be surprised to see it used much outside the PS 3 and the Sony dev stations for the next 5 years or so. Only if it proves to be vastly superior in real world use then will it have a chance to progress beyond that circle.

Cell doesn't exist yet. I'm just supremely excited that someone decided to do something different. This would be like reading about MIPS in the early 80's. Perhaps even bigger. It's hard to say. People will have to change the software paradigm eventually, since anyone who knows anything about microprocessors will colorfully explain to you that the way we're going know, just pushing more electrons in shorter intervals, is a suboptimal solution. It's a sequential solution. The human brain works in parallel, and is better than any computer today by quite a margin in terms of overall capability. In engineering much of what we do is mimic nature, and computers shouldn't be an exception.

As for my excitement about embedded use, it appears that it will be easy for any provider to built many types of custom cell chips that are best suited to do various things. This is great for embedded computing. no doubt about it. Instead of being bottlenecked, and having to use -- say -- a 400Mhz XScale even though only one, tiny component of your requirements need that kind power, I could use a cell will an encryption block that only draws power when it's in use. That would rock. Using an ecryption ASIC is another way to do it, but with the cell it's all on a die, and it's all possible through software. Outside of the embedded realm, power is less of an issue. Lastly, encryption ASICs these days are usually just off-the-shelf MCUs with a program loop in the ROM. The Cell solution would be the same from a low level perspective, but would be easier to implement. (Hardware drivers already done.)

Just out of curiosity, where are you getting this information? I'm not an expert on CompArch (my focus is on communications, signals, analog, etc.), but generally speaking I do know way more than average about computers, given that I have a degree in EE and have programmed my fair share of embedded devices.

Originally posted by AirSlufCell is going to be a bitch to write software for. It is a new paradigm and Sony has not yet put software dev kits in the mainstream.

It doesn't strike me as any newer than, say, SmallTalk.

The main obstacle will be that, for historical reasons, game designers are used to writing monolithic, single-threaded apps for single-core CPUs. But the idea of massive MP, and the languages and programming techniques suited to massive MP, are fairly old and well-understood. The only real wrench that Cell throws in is that it's asymmetric MP. The main issue would be making the message-passing code as efficient as possible, because the architecture carries a real risk of drowning itself in overhead.

As I mentioned above, to the extent that individual hardware cells will be standard, developers and platform vendors can build and/or offer software "actors" to match them. Once there, this looks great for games, which characteristically have lots of independent actors () simultaneously following relatively simple logic.

Originally posted by AmorphThe main obstacle will be that, for historical reasons, game designers are used to writing monolithic, single-threaded apps for single-core CPUs. But the idea of massive MP, and the languages and programming techniques suited to massive MP, are fairly old and well-understood. The only real wrench that Cell throws in is that it's asymmetric MP. The main issue would be making the message-passing code as efficient as possible, because the architecture carries a real risk of drowning itself in overhead.

I am recalling something I read a couple of years ago, so, please correct me if I am wrong; however, the current PS2 uses more than one processing unit: a DSP chip, RISC CPU, GPU, any else? The difficulty initially was that the API's required developers to wrote code for each chip and pass messages (of course, each chip was a different architecture requiring even more learning curve).

I would think that good PS2 development houses would have little trouble with the Cell paradigm.

EDIT: I forgot to add...

Back on topic, I really do not see the Cell design as something that will translate to Apple's products. The only benefit from Cell to Apple I can see is what wizard69 referred to: teaching IBM how to deliver mass quantities at low prices.

Originally posted by atomichamI am recalling something I read a couple of years ago, so, please correct me if I am wrong; however, the current PS2 uses more than one processing unit: a DSP chip, RISC CPU, GPU, any else? The difficulty initially was that the API's required developers to wrote code for each chip and pass messages (of course, each chip was a different architecture requiring even more learning curve).

I would think that good PS2 development houses would have little trouble with the Cell paradigm.

This is true. Consoles have featured dedicated hardware for years, so this will be nothing new. It'll just be on a smaller scale. to add...

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Back on topic, I really do not see the Cell design as something that will translate to Apple's products. The only benefit from Cell to Apple I can see is what wizard69 referred to: teaching IBM how to deliver mass quantities at low prices.

The major stumbling block I see is AltiVec, which can't be broken up into pieces without losing a great deal of its power, and which would make a relatively Brobdignagian cell - really, it depends on how uptight IBM is about grandfathering a big pile of transistors into their pretty new design (last time this came up, remember, they turned their nose up).

Besides that, I think this has considerable promise for Apple down the road. They've already hitched their wagon to a message-based OO language and a messaging kernel (even if they've taken some liberties with Mach). If IBM can make AltiVec a "cell" then it shouldn't be hard to assemble a cell-based processor that looks pretty much like a conventional CPU in terms of its aggregate capabilities.

Where it gets interesting is: By deconstructing a monolithic core into lots of little cores on a fabric, IBM is requiring any cell-based software to maintain a fairly high-level logical view of the "CPU" it runs on. From there, it's a small step to distributing the "CPU" over the board as convenient. So, assuming that IBM offers a standard bin of Cell parts, Apple could choose to put a couple of DSP cells on the memory controller. All the software would have to be aware of is that the messages between those cells and the others would be higher latency - and Objective-C and Cocoa already acknowledge low-latency and high-latency messages, by analogy (intraprocess and interprocess messaging). Then Apple could offload common transforms to dedicated hardware from a standard parts bin, and offset the increasingly high latency of system busses by distributing the CPU logically.

Maybe I'm barking up the wrong tree, but this could really go somewhere interesting.

Interesting thoughts Amorph. I have not been reading exactly how cell processors work, but if your saying cells can be specific cores, such as an Altivec core I guess it could be possible in a multi core processor system to dedicate an Altivec, or SIMD cell core for FPU (because that is all it handles is Floating point #'s) with double, or more the current Altivec bandwidth, and have a group of cell cores per-processor maybe 2 to 4 to do equal the mathematical output of the Altivec, or SIMD FPU's so all the mathematical instructions could just fly through with the quickness.
That is how should be done IMO if possible. Because Altivec is very impressive for what it does (FP#'s), but the rest of the math was handled no differently other than it wasn't handling the Floats. You would almost think it could be possible to have cores for Long, Short, Float, and so on in a single chip.

Originally posted by onlookerBecause Altivec is very impressive for what it does (FP#'s), but the rest of the math was handled no differently other than it wasn't handling the Floats. You would almost think it could be possible to have cores for Long, Short, Float, and so on in a single chip.

Anyway, just a rant.. Nothing to see here.. move along..

Altivec is an 128bit VPU. It can do 16 bytes, 8 short ints, 4 32bit integers, 2 double precision floating point ops, etc. It is useful for many things, as long as the programmer isn't a chump.

But I would imagine that the affect of Altivec could be emulated through the Cell system without a huge pile of transistors necessary. Really, it just seems like adding a couple more general purpose ALU/FPU units, and tying them to the main network as well as putting them in close proximity to each other with a little optional control logic, so when Altivec instructions are called, they are handled by this lobe of sorts. If the system already computes a great deal of its arithmetic in parallel, Altivec isn't going to deliver a real speed bonus. Instead, it's just backwards compatibility, and when Cell variants get in macs a bit down the road, I bet we'll see a shift they way we did with the Mac->Power Mac upgrade. So I don't really see why Altivec is necessary.

Since the PS2, middleware has become a lot more common in the console world and I expect it to become even moreso in the future. If the middleware developers get it right, then by default, the game programmers will too.

"Hearing a corrupt CEO like Cheney denigrate Edwards for being a trial lawyer is like hearing a child molester complain how Larry Flint is a pervert." -johnq

Not really. If you sift through all of the information available on Cell it appears to come down to something as simple as asymmetric cores on a single chip with an unconventional memory addressing/sharing scheme. The main core is probably fairly traditional, and quite possibly PowerPC. The additional cores are more along the lines of PS2 vector units. There is nothing about sharing execution units or reconfiguring circuitry -- that stuff is all on the distant horizon but considerably farther out than the Cell delivery date. If the main core of a Cell chip is PowerPC then it could include an AltiVec unit, or it might not. The additional vector cores would execute a different instruction set entirely that includes its own set of vector operation primitives.

Could Apple use such a thing? If its main core is a true PPC32 or PPC64, then possibly -- they've had machines with DSPs in them in the past, plus there have been rumours of add-on media processors and vector units in the main chipset. Since this kind of thing is asymmetric you need to code for it specifically, or have some kind of higher level system service that converts your operations to run on the available hardware (a la CoreImage and OpenGL 2). Whether this is better than a multi-core version of the 9x0 series is an open question. High clock rates have been postulated for the Cell (and XBox2, for that matter) but all of that information appeared before the 970FX tripped over its feet and then finally arrived at "only" 2.5 GHz wearing a water tank on its back.

Kickaha and Amorph couldn't moderate themselves out of a paper bag. Abdicate responsibility and succumb to idiocy. Two years of letting a member make personal attacks against others, then stepping aside when someone won't put up with it. Not only that but go ahead and shut down my posting priviledges but not the one making the attacks. Not even the common decency to abide by their warning (afer three days of absorbing personal attacks with no mods in sight), just shut my posting down and then say it might happen later if a certian line is crossed. Bullshit flag is flying, I won't abide by lying and coddling of liars who go off-site, create accounts differing in a single letter from my handle with the express purpose to decieve and then claim here that I did it. Everyone be warned, kim kap sol is a lying, deceitful poster.

Now I guess they should have banned me rather than just shut off posting priviledges, because kickaha and Amorph definitely aren't going to like being called to task when they thought they had it all ignored *cough* *cough* I mean under control. Just a couple o' tools.

Kickaha and Amorph couldn't moderate themselves out of a paper bag. Abdicate responsibility and succumb to idiocy. Two years of letting a member make personal attacks against others, then stepping aside when someone won't put up with it. Not only that but go ahead and shut down my posting priviledges but not the one making the attacks. Not even the common decency to abide by their warning (afer three days of absorbing personal attacks with no mods in sight), just shut my posting down and then say it might happen later if a certian line is crossed. Bullshit flag is flying, I won't abide by lying and coddling of liars who go off-site, create accounts differing in a single letter from my handle with the express purpose to decieve and then claim here that I did it. Everyone be warned, kim kap sol is a lying, deceitful poster.

Now I guess they should have banned me rather than just shut off posting priviledges, because kickaha and Amorph definitely aren't going to like being called to task when they thought they had it all ignored *cough* *cough* I mean under control. Just a couple o' tools.

As a game designer I would say that the cell apprach will be fun. As of now I am not writing my game to work with todays tech. I intend for it to be released when they are dual core dual proc smt systems with more than one GFX chipset. May run like crap now. But eventualy it will be nice having my as of right now 12 threads running on their own logical unit. When it comes to the programming its not that hard switching the desing paradigms, its harder to switch your data paradigms. How you look at, orgamize and operate on the data becomes weird. Kinda of like writing things for altivec, that really strain my brain. but yeah, what I meant to say is that I don't think that cell will do badly, but For now I do not believe the implementation in the PS3 or the workstation will be impressive enough to me compared to say the SMP route that all the chip maker are leaning to.

Originally posted by ProgrammerNot really. If you sift through all of the information available on Cell it appears to come down to something as simple as asymmetric cores on a single chip with an unconventional memory addressing/sharing scheme. The main core is probably fairly traditional, and quite possibly PowerPC. The additional cores are more along the lines of PS2 vector units. There is nothing about sharing execution units or reconfiguring circuitry -- that stuff is all on the distant horizon but considerably farther out than the Cell delivery date. If the main core of a Cell chip is PowerPC then it could include an AltiVec unit, or it might not. The additional vector cores would execute a different instruction set entirely that includes its own set of vector operation primitives.

Interesting, because I'd read that from various (public) sources, including IBM slides posted at Ars, that IBM was going significantly multicore, first of all, versus dual-core now, and second of all that the Cell cores were incomplete and special purpose (partly so that they could clock really high, another thing I've seen on an IBM slide).

If all it is is a nifty fabric for traditional AMP or SMP on die &mdash; and I have no reason to doubt you on this &mdash; then... meh. I honestly had the impression from reading around that IBM were trying for a paradigm shift rather than an incremental improvement.

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Could Apple use such a thing?

It's much easier to imagine them using this far more conservative design strategy than the more far-out one that I'd imagined, certainly. It'll make a nice competitor to the 8641D coming out from Freescale next year. But that's all.

Originally posted by AmorphInteresting, because I'd read that from various (public) sources, including IBM slides posted at Ars, that IBM was going significantly multicore, first of all, versus dual-core now, and second of all that the Cell cores were incomplete and special purpose (partly so that they could clock really high, another thing I've seen on an IBM slide).

Well the Cell is significantly multi-core (8+ cores is pretty significant), and the Cell cores are specialized vector execution units, and they probably will clock higher than a general purpose core could. But what I'm saying is that they are still only several specialized high clock cores on a single die. That's a far cry from what was being discussed a few posts back.

This is a major paradigm shift for most software to deal with... right now everyone is pretty much coding for one or two SMP threads. That is a lot different.

If the Cell cores are PowerPC, cheap and high frequenzy is there a possibility that we might see Cell based accelerator cards? If ATI thinks they can use the main RAM as VRAM using the high bandwidth PCIe bus, woundn't it be possible to strap on a dozen Cells on a PCIe card and make a fairly cheap accelerator card for general number crunching, 3D, video rendering and such?

Originally posted by Programmer
Not really. If you sift through all of the information available on Cell it appears to come down to something as simple as asymmetric cores on a single chip with an unconventional memory addressing/sharing scheme.

In my limited surfing this is what I've come up with. Those cores are apparently PPC or PPC derived with the obvious new cores to support additional functionality.

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The main core is probably fairly traditional, and quite possibly PowerPC. The additional cores are more along the lines of PS2 vector units. There is nothing about sharing execution units or reconfiguring circuitry -- that stuff is all on the distant horizon but considerably farther out than the Cell delivery date. If the main core of a Cell chip is PowerPC then it could include an AltiVec unit, or it might not. The additional vector cores would execute a different instruction set entirely that includes its own set of vector operation primitives.

What I wonder is how much room is there to improve Alt-Vec with respect to doing vector operations. Will 4 cores, each working on a 16 or 32 bit vector be better than the Alt-Vec approach?

The bigger problem as I see it is that Cell has to implement a 64 bit processor to remain viable for more than a year or two. I really believe that the addressing range 64 bits offers will be significant in a short time in this market.

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Could Apple use such a thing? If its main core is a true PPC32 or PPC64, then possibly -- they've had machines with DSPs in them in the past, plus there have been rumours of add-on media processors and vector units in the main chipset. Since this kind of thing is asymmetric you need to code for it specifically, or have some kind of higher level system service that converts your operations to run on the available hardware (a la CoreImage and OpenGL 2).

The reality here is that Apple has had prior expereince here with DSP and frankly it did not go over well. Since Apple has a well recieved, but partial, DSP facility in Alt-Vec it would seem to make more sense to simply extend Alt-Vec to make use of the additional transistors available to them.

Apple needs to offer a uniform programming environment, it is pretty obvious that they undestand this as they have switched over to all Alt-Vec enabled processors. Now that doesn't mean that Apple could build the software required to offer the Alt-vec programming environment on Cell if it doesn't already exist there. I just have a very hard time seeing the payoff for the types of applications that Apple hardware runs. In other words it wouldn't make much sense to tye up the entire Cell chip just to emulate Alt-Vec especially when hardware performance is still moving forward with conventional implementations.

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Whether this is better than a multi-core version of the 9x0 series is an open question. High clock rates have been postulated for the Cell (and XBox2, for that matter) but all of that information appeared before the 970FX tripped over its feet and then finally arrived at "only" 2.5 GHz wearing a water tank on its back.

I had to laugh here a bit. The water tank on its back reminded me of the old fashion steam engines with their saddle tank water resivoirs.

I'm still of the opinion that the existance of the water cooling system in Apples hardware is pretty clear indications of IBM's failure to meet customer expectations. We do not see a whole lot of water cooling going on in the AMD 64 bit world, and very little if any in the rest of the 90nm world. More than anything I see this as a driver at Apple to search out new technologies and vendors. I just don't see Cell being this alternative.

The main obstacle will be that, for historical reasons, game designers are used to writing monolithic, single-threaded apps for single-core CPUs.

Where did you get that idea from? Us console and arcade engineers have been writing games for multi-chip systems for as long as I've been in the business, over a decade. Sound, physics, AI/game logic are all broken up into sub-programs running in parallel on different chips in the machine to various degrees depending on hardware.

Originally posted by TuttleWhere did you get that idea from? Us console and arcade engineers have been writing games for multi-chip systems for as long as I've been in the business, over a decade. Sound, physics, AI/game logic are all broken up into sub-programs running in parallel on different chips in the machine to various degrees depending on hardware.

My bad, especially since I made exactly the same point elsewhere in the thread! I meant Windows game programmers.

Originally posted by wizard69What I wonder is how much room is there to improve Alt-Vec with respect to doing vector operations. Will 4 cores, each working on a 16 or 32 bit vector be better than the Alt-Vec approach?

This doesn't jive with my understanding. If a Cell chip is a main PowerPC core with 8 vector cores this means it will be executing 9 different instruction streams: 1 stream of PowerPC instructions and 8 streams of whatever instructions the vector cores use (probably not PowerPC). Each vector core will be able to do operations similar in nature to what AltiVec currently does on the G4 or G5. In other words the Cell will be (theoretically) capable of 9 times the computation if running at the same clock rate (and the Cell's clock rate will likely be substantially higher). To support this level of computation they have developed a memory scheme that is different than the traditional PowerPC model. It also goes without saying that existing code won't just work on the Cell's vector cores... but this is just as well since these vector cores aren't likely to be out of order superscalar processors like the 970 is so careful coding and algorithmic redesign will be required to run at all, nevermind get peak performance.

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The bigger problem as I see it is that Cell has to implement a 64 bit processor to remain viable for more than a year or two. I really believe that the addressing range 64 bits offers will be significant in a short time in this market.

Given its target market in the embedded and console space, I don't think this is a requirement. Also, with a substantially different memory addressing scheme it might not be necessary to go to 64-bit pointers to acheive larger memory sizes. The scalar integer units may well be 64-bit, however -- at least on the main core. The cost in terms of processor complexity is not that high.

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The reality here is that Apple has had prior expereince here with DSP and frankly it did not go over well. Since Apple has a well recieved, but partial, DSP facility in Alt-Vec it would seem to make more sense to simply extend Alt-Vec to make use of the additional transistors available to them.

On the other hand they still provide a considerable amount of system services which use hardware acceleration internally. The OpenGL shaders, CoreAudio, CoreImage, QuickTime, vector library, network stack, etc could all be re-optimized over time to take advantage of specialized hardware. Nonetheless I tend to think that Apple would rather stick with the traditional PowerPC w/ AltiVec programming model and start adding cores. I don't actually expect to see Cell in Apple's future.

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In other words it wouldn't make much sense to tye up the entire Cell chip just to emulate Alt-Vec especially when hardware performance is still moving forward with conventional implementations.

Cell cannot "emulate" AltiVec. They are two different beasts.

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I had to laugh here a bit. The water tank on its back reminded me of the old fashion steam engines with their saddle tank water resivoirs.

Well I'm glad somebody got the joke.

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I'm still of the opinion that the existance of the water cooling system in Apples hardware is pretty clear indications of IBM's failure to meet customer expectations. We do not see a whole lot of water cooling going on in the AMD 64 bit world, and very little if any in the rest of the 90nm world. More than anything I see this as a driver at Apple to search out new technologies and vendors.

AMD isn't at 90 nm yet and they recently pushed back their scheduled move to that process. I think Apple's use of water cooling on the 2.5 GHz machines was a direct result of a deep desire to keep the machines quiet and deal with the very significant heat density issues that result from being able to suddenly expend such a huge amount of power from such a small area. These G5s can go from very low power consumption to very high power consumption very quickly and water has the specific heat capacity to absorb that initial spike without having to continuously keep fans blowing at full speed. If the darn unit didn't looks so... so... automotive then it might actually be a compelling piece of technology.

Originally posted by TuttleWhere did you get that idea from? Us console and arcade engineers have been writing games for multi-chip systems for as long as I've been in the business, over a decade. Sound, physics, AI/game logic are all broken up into sub-programs running in parallel on different chips in the machine to various degrees depending on hardware.

While that is true, the coming machines are somewhat different in nature. There are going to more cores than ever before and they are going to be more general purpose than ever before. This presents some new challenges to get peak performance from this hardware.

I want you to know that I had a great respnse to this post yesterday but the server apparently started having problems. So here is an attempt at a condenced version.

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Originally posted by Programmer
This doesn't jive with my understanding. If a Cell chip is a main PowerPC core with 8 vector cores this means it will be executing 9 different instruction streams: 1 stream of PowerPC instructions and 8 streams of whatever instructions the vector cores use (probably not PowerPC). Each vector core will be able to do operations similar in nature to what AltiVec currently does on the G4 or G5.

What is clear is that I really don't have much information here, the issue is that I'd be surprised if those 8 vector cores are as wide as the Alt-Vec unit in PPC. What I see is 8 cores of very modest width (maybe one word) that are used together in various combinations.

The problem as I see it is that having that many cores of the Alt-Vec type will take up a huge amount of room. Not just for the cores but for the supporting caches and communications logic. I just don't see current processes supporting that many Alt-Vec type units well on one chip.

The other problem is the efficency of that sort of implementation. Making full use of that many wide vector units would be a problem. Thus the thought that the vector units would be narrow devices, very much like many of the DSP's available today.

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In other words the Cell will be (theoretically) capable of 9 times the computation if running at the same clock rate (and the Cell's clock rate will likely be substantially higher). To support this level of computation they have developed a memory scheme that is different than the traditional PowerPC model. It also goes without saying that existing code won't just work on the Cell's vector cores... but this is just as well since these vector cores aren't likely to be out of order superscalar processors like the 970 is so careful coding and algorithmic redesign will be required to run at all, nevermind get peak performance.

I read this and think that maybe you know more about Cell than you are willing to let on Even so the implied simple execution units lead me back to thinking narrow vector units.

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Given its target market in the embedded and console space, I don't think this is a requirement. Also, with a substantially different memory addressing scheme it might not be necessary to go to 64-bit pointers to acheive larger memory sizes. The scalar integer units may well be 64-bit, however -- at least on the main core. The cost in terms of processor complexity is not that high.

64 bits will be huge in the future. In the case of Cell I think it would simplfy things more than anything. As you say the cost isn't that high.

On the other hand the embedded an console market is heading towards 64 bit machinery. It is simply a matter of getting costs under control, with memory beign the big issue. So we are talking a year or two before large memory systems are cost effective. I can't see this team designing a chip that is only going to be competitive for a year or two.

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On the other hand they still provide a considerable amount of system services which use hardware acceleration internally. The OpenGL shaders, CoreAudio, CoreImage, QuickTime, vector library, network stack, etc could all be re-optimized over time to take advantage of specialized hardware. Nonetheless I tend to think that Apple would rather stick with the traditional PowerPC w/ AltiVec programming model and start adding cores. I don't actually expect to see Cell in Apple's future.

I see Cell in Apples future but maybe not in the way you see it. I see Cell as an opportunity on IBM's part to optimize the execution units within the PPC line. What would be really neat is if Cell lead to hand crafted execution units to replace the dense sea of logic that is the 970 we all know and love. The idea here being to replace some of the hot stuff within the 970's.

So hopefully Cell becomes a proving or development framework for things that can be extended to the 970 series.

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Cell cannot "emulate" AltiVec. They are two different beasts.

I'm not sure you meant to say that. Obviously Cell can emulate anything it wants to emulate, that is simply a matter of writing the right code.

What I was getting at and this is only a consderation if Apple is interestedin Cell, has there been an attempt to design the Cell vector units so they could emulate or work in place of, in an efficent manner the Alt-Vec units.

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Well I'm glad somebody got the joke.

AMD isn't at 90 nm yet and they recently pushed back their scheduled move to that process. I think Apple's use of water cooling on the 2.5 GHz machines was a direct result of a deep desire to keep the machines quiet and deal with the very significant heat density issues that result from being able to suddenly expend such a huge amount of power from such a small area. These G5s can go from very low power consumption to very high power consumption very quickly and water has the specific heat capacity to absorb that initial spike without having to continuously keep fans blowing at full speed. If the darn unit didn't looks so... so... automotive then it might actually be a compelling piece of technology.

That automotive look is technology none the less. Old technology yes but well understood and reliable.

The G5's though are just the opposite. Very new technology that frankly has not meant expectations of anybody. That is not to say that the 970's don't work, just that they haven't gotten to where people (JOBS) had expected. What is worst they didn't get there and where they are now is problematic.

It is all well and nice that IBM has a 90nm process but we shouldn't forget that the process needs alot of work. Instead of claiming to have hit a wall IBM really should be saying they are working on breaching the wall. Otherwise one is left with the impression that PPC doesn't mean much to them. IBM needs a leading edge 90nm process not a trailing edge process.